1. Field of the Invention
The present invention relates to a method and an apparatus of manufacturing a reflector.
2. Description of the Related Art
In portable electronics such as a portable telephone or a portable game device, since the battery life extremely affects usability, a reflective-type liquid crystal display device having low power consumption has been employed as a display device. The reflective-type liquid crystal display device comprises a reflector for reflecting external light incident from the front surface thereof. In the construction thereof, it is known that the reflector is sandwiched between two substrates forming the liquid crystal panel, or the semi-transmissive reflector is positioned on the rear surface of a transmissive liquid crystal panel. As the semi-transmissive reflector, a reflector having fine holes for transmitting the light is known.
As a conventional reflector, the reflector having a plurality of concave portions formed therein is known, as described in the below Patent Document 1. In order to manufacture this reflector, as described in Japanese Unexamined Patent Application Publication No. 11-52110, a method of preparing a transfer plate and a resin base material made by forming a photosensitive resin layer on the plate, pressing the transfer plate against the photosensitive resin layer of the resin base material, and then irradiating ultraviolet rays thereto to cure the resin base material is employed.
On the other hand, as a means for applying a specific shape to the surface of the photosensitive resin on a flexible sheet, as described in Japanese Unexamined Patent Application Publication No. 8-54503, a method of sequentially transferring the shape of the transfer pattern by forming transfer pattern on the surface of a rotary roller and pressing the rotary roller against the photosensitive resin layer while rotating the rotary roller is known. In addition, in this method, by irradiating ultraviolet rays onto the portion where the rotary roller contacts the photosensitive resin, the transferring step and the resin curing step are simultaneously performed.
However, in the case of manufacturing the semi-transmissive reflector by the method of Patent Document 2, fine holes for transmitting light must be formed in the photosensitive resin. But, in the method of Patent Document 2, since the transferring step and the resin curing step are simultaneously performed such that the photosensitive resin is completely cured, it is difficult to form fine holes in the photosensitive resin after the transferring step. Accordingly, the method of Patent Document 2 is not suitable as the method of manufacturing the semi-transmissive reflector which requires further processing after the transferring step. Also, the rotary roller cannot be pressed against the inflexible base material sheet by a sufficient area, thereby decreasing productivity.
Accordingly, in the method of Patent Document 2, it is considered that the step of irradiating the ultraviolet rays onto the photosensitive resin layer may follow the transferring step and the fine hole forming step. However, since the photosensitive resin layer has relatively large flexibility, the transferred shape of the photosensitive resin may be naturally changed while forming the fine hole. Also, by performing the transferring step while rotating the rotary roller, points of time between the start and end portions of the sheet are different, thereby changing the time up to the ultraviolet ray irradiating step. Thereby, during irradiating the ultraviolet rays, the shape of the start portion of the sheet may be largely changed.